Improvement in photographic cameras



UNITED STATES PATENT OFFICE.

ALLEN B. WILSON, OF IVATERBURY, vCNNEOTICUTa IMPROVEMENT lN PHOTOGRAPHIC CAMERAS.

Specification forming part of Letters Patent No. 34,800, dated March 25, 1862.

To all whom it may concern.-

Be it known that I, ALLEN B. WILsoN, of Va-terbury, New Haven county, and State of Connecticut, have invented a new and Improved Photographic Camera; and I hereby declare that the following' is a full, clear, and exact description of my invention, reference being had to the accompanyingdrawings, making a part of this specification, and the letters of reference markedthereomin which the same letter represents the same thing in each figure.

Figure l is a side view of myimproved photographic cameradoox. Fig. 2 is a top view of the same. Fig. 3 is a sectional side view eut through the center. Fig. et is a front view of the combined back and plate -holder surrounded by the box in section and with the funnel and key attached. Fig. 5 is a back view of the same.

A represents the box; B, the camera-tube; C, the door; D, the key; E, the crooked-stem funnel; F, the back spring of the negativeplate holder; G, the negativeglass; II H, the journals; I, the channel through which the baths flow forth and back from the funnel to the negative-glass; J, the throat of the same.

The usual method of taking a negative for a photograph is thus: After placing the camera and adjusting the focus the plate lfor the negative is to be prepared. Being-first coated with collodion, it is immersed inabath of nitrate of silver, which immersion must take place in a dark-chamber. It is then placed in the camera and exposed to the object. After exposure the negativeplate is retaken to the dark-chamber and the picture developed by the secondbath. After that it maybe washed off in the light. This process, carried on out of doors, is not unattended with difficulties. First, the absence of a dark-room often necessitates carrying and pitching a tent; second,

carrying baths to be unsealed and sealed at every move; third, Wind and dirt endanger' the bath when open and it is liable to be up set and lost in the dark-room or tent; fourth, working and keepingwork clean in the dark and exposure of hands and clothing to theinfluence of chemicals, and, fifth, loss of time in traveling back and forth between the camera and the darkchamber, first to sensitize and then to develop.

To save pitching a tent, a dark-room is some tim es obtained in a dwelling or out house not too remote from the object. The success of the undertaking is very much a matter of luck, depending upon a series 'of delicate manipulations carried on in the dark.

My purpose is to avoid these vexations and troubles and reduce the process by mechanical aids to so simple a matter that a gentleman may take a picture without soiling his iingers and the pedestrian be equipped with the stand in his hand, camera under his arm, and two vials and a few plates in his pocket. I accomplish it thus: I employ a box A, wide and high enough to contain the negative-plate holder K, in one end of which is the ordinary camera-tube B and at the otheradoor C, shutting tight, making the box a dark-chamber. Near the center of the sides of the box are bearings L L, in which the holders of the focus and negative glasses may turn up and down. They are turned by a key inserted from the outside of the box into a square hole in the left journals.

I combine the holder for the negative-glass and the bath in one instrument. This holder and bath is made of hard rubber to resist chemicals. It has a rubber-packed joint and spring and snap at the back to hold the negative-glass fluid-tight in its position. It is of course open in front to secure exposure. The right journal is hollow, and into it fits an adj ustable crooked-stem funnel inserted from the outside of the box. It is crooked tokeep out light and to facilitate pouringhout as well as in through a single orifice in the journal.

To use the instrument, the focus-glass holder being placed in the bearings, the key turns it perpendicular and the focus is obtained. That glass being removed, the negative-glass is coated with collodion, placed on the rubber packing' of the plate-holder, and secured by the spring and snap, the collodion toward the oval opening. It is then placed horizontally in the bearings in the box, the door shut, and the key inserted in the left and the funnel in the right journal. From a vial nitrate of silver is then poured into the crooked-stem funnel, through which it passes and flows evenly over the surface of the collodion-eovered plate. After a proper time for sensitizing has elapsed the turning of the key turns the plate perpen dicular and the nitrate of silver runs off the plate andback through the Vcrooked-stem funnel, Which'tnrns down -as the plate assumes the perpendicular into the vial. The plate is then exposed to the object through the lens. The key turns the plate horizontal again, and the second or developing bath is introduced and removed, as was the-rst. The funnel and key may then. be removed and the negative cleaned in the light. After removing the plate the bath-holder should be thoroughlycleansed. A tooth-brush is as handy an instrument as any for the purpose. The same result may be reached in this way: Place the combined bath and plate holder perpendicular, introduce a tube down its back to the bottom, admit thereby the bath under the plate, and let it ilow upward. A slide with a fluidtight joint will be required in front of the negative-glass, to be removed when the point of exposure is reached; also, a second tube at the bottom to draw oit' Ithe baths.

The advantages of my method are obviousA I get rid of the slide and second fluid-tight joint, of the second tube, less silveriswasted,

and every partof the plate equallyimmersed. l

NVhat-I claim, and desire to secure by Letters Patent, is-

l. A negative-plate and bath holder having a hollow journal, channel, and throat, constructed and operating substantially as and for the purposes described.

2. The hollow journal described for introducing and withdrawing the baths.

3. The combination of negative-plate and bath holderhaving,` a hollow journal, channel, and throat as oneinstrument,with the crookedstem funnel, constructed and operating substantially as described.

4. Giving the combined negative-plate and bath holder the capacityof assuming horizontal and perpendicular positions at will,in the manner and for the purposes described.

5. The combination of camera-box, crookedstem funnel, hollow journal, channel, and throat, an d Huid-tight holder, substantially as described.

ALLEN B. WILSON.

lVit-ncsses:

S. J. GORDON, GEO. H. COLLINS.

"Edif N 

